Also known as a PJ (Personal Joke), an IJ is an Inside/r Joke. For the jokes that are shared between 2-4 friends, that NOONE else will understand. CAUTION: Creating millions of IJ's may cause people to doubt your sanity.

Rachee: Did ya do my blog?
JoJo: Yeah gee! I put loads of IJ's in it :L

A suffix deriving from -age that is occasionally seen in slang that basically turns a verb into a noun. It's been known to be used when there is a character limit where it is preferable over -age as it has fewer letters.